The design and use of cable cutters to be operated in the ocean environment has become of great importance in the field of marine engineering. Cable cutters have been of extreme interest to the U.S. Navy. One major Navy application is for minesweeping operations. Operation of cable cutters is presently being extended to all depths of the world's oceans.
The design and construction of cable cutters cover an extensive area of the engineering fields. The general method used for cutting is a mechanical technique usually involving a cutter impinging on an anvil to cut the cable or wire. In some cases scissor-like devices have been used. Operation of the cable cutter has included the manipulation of the cutter at the cable by a diver, either remote or hands-on operation of a cutter which is actuated by the force of contact with the cable, and by remote means using electrical wires to actuate an explosive firing mechanism. Generally, such cable cutters have been designed as expendable in that they can only be used to cut once and are either lost or destroyed by that operation.
Originally, cable cutters were designed mostly for cutting simple wire ropes and electrical cables. Modern state-of-the-art for electrical cable construction has resulted in the use of KEVLAR as a strength member. KEVLAR is a tough synthetic fiber and cannot easily be cut by scissor mechanisms. Consequently, many new designs for various types of cable cutters have been presented during the recent years. These have generally incorporated powerful anvil/cutter blade mechanisms.
Modern cable cutting technique is also being applied to underwater deep submergence vehicles. Cutters have been designed which mount to such vehicles and can be manipulated by an operator located inside the vehicle. Cable cutters designed for use at great ocean depths have been required to be heavy and bulky in order for certain pressure sensitive components to withstand and high hydrostatic pressures. This is particularly true where hydraulic systems have been used to provide a powerful cutting force. The essence of the present invention is the presentation of an improved hydraulic cable cutter which is designed to be lightweight and to operate from, and mate with, the manipulators of a deep submergence vehicle.